最重要的决定是你对世界的态度。

Education is the foundation of conservation—people protect what they understand.

生命的终结是幸福，而幸福是宁静。

很多时候，我们都需要面对选择。如果都有好处，就要取其中好处最大的；如果都有害处，就取其中害处最小的。

Freedom does not consist in any dreamt-of independence from natural laws, but in the knowledge of these laws, and in the possibility this gives of systematically making them work towards definite ends.